2. Erythrocyte Sedimentation Rate (ESR) Muhammad Munir Senior phlebotomist The Indus Hospital (Multan Institute of Kidney Disease)

3. ESR It is the rate of downward descent of RBCs in a vertical column of blood.

4. Principle of ESR If anti-coagulated blood is allowed to stand vertically in a narrow tube, the red cells will settle progressively to the bottom leaving clear plasma above. The cells settle due to : 1-Density of RBCs is greater than that of plasma. 2-RBCs tend to aggregate to form Rouleaux. (Rouleaux differs from agglutination that agglutinated cells are irreversibly bound together and can not be separated )

5. Stages of ESR  There are 3 stages in erythrocyte sedimentation Process. Stage 1 : Rouleaux formation - First 10 minutes Stage 2 : Sedimentation or settling stage – 40 minutes Stage 3 : Packing stage - 10 minutes (sedimentation slows and cells start to pack at the bottom of the tube)

6. Collection of ESR Specimen Specimen type: Whole blood Preferred collection container: ESR Vacuum Tube (3.8 % Sodium Citrate), lavender-top ( EDTA) tube Specimen required: Whole Blood Specimen volume:4ml Do not centrifuge. Specimen must be sent as whole blood.

7. Methods of ESR 1. Westergren Method 2. Wintrobe Method 3. Modified Westergren Method 4. Automated Method

8. Comparison of Wintrobe & Westergren Method

9. Clinical Significance of ESR

10. Reference range  Adults: Men under 50 years old <15mm/hr Men over 50 years old <20mm/hr Women under 50 years old <20mm/hr Women over 50 years old <30mm/hr  Children: New born 0-2 mm/hr New born to Puberty 3-13 mm/hr

11. Factors affecting ESR

12. Clinical Application of ESR Nonspecific test. Prognostic not diagnostic. Monitor disease activity and response to therapy. ESR is a nonspecific marker of inflammation and is affected by other factors, ESR results must be used along with other clinical findings.